Python 3: 'bytes' object has no attribute 'format'

[khudyakovavi]

There is no support for bytes .format in python3.
An error occurred at

pyprometheus/pyprometheus/contrib/uwsgi_features.py

Line 377 in 2b2e840

return struct.unpack(b"{0}s".format(size), key_string_bytes)[0]